L137 Blue Eyed Red Fin Pleco - (Hypostomus soniae)

Fish Details, Description and Information Below:

🔵 L137 Blue Eyed Red Fin Pleco – (Hypostomus soniae) – Wild-Caught Rio Tapajós Pleco

The L137 Blue Eyed Red Fin Pleco (Hypostomus soniae), also known as the Blue-Eyed Redfin Pleco, Rusty Pleco, Violet Pleco, or Blue-Eyed Cochliodon Pleco, is a distinctive Brazilian pleco known for its unusual combination of bright blue to blue-gray eyes, warm rust-colored fins, and a dark olive, brown, gray, or violet-toned armored body.

Unlike many plecos prized primarily for:

Spots
Stripes
Zebra markings
Bright body patterns

the L137's most recognizable feature is its:

BRILLIANT BLUE EYES

combined with reddish, rust-orange, or bronze coloration through the fins.

The L137 is native exclusively to Brazil's:

RIO TAPAJÓS BASIN

in Pará State.

It belongs to the unusual:

Hypostomus cochliodon Species Group

whose members possess specialized spoon- or chisel-shaped teeth and spend considerable time rasping submerged wood and consuming wood-associated:

Detritus
Biofilm
Algae
Microorganisms
Plant material

Scientific studies of the Hypostomus cochliodon group have found their digestive tracts can contain large quantities of wood particles, making L137 quite different nutritionally from many typical Hypostomus.

However:

WOOD SHOULD NOT BE CONSIDERED A COMPLETE DIET

and we do not recommend claiming that the fish must digest wood cellulose for proper digestion.

A healthy L137 should receive:

DRIFTWOOD + PLANT-BASED FOODS + BIOFILM + A VARIED OMNIVOROUS DIET

with modest supplemental animal and insect protein.

This is a substantial, high-backed pleco capable of reaching approximately:

7–9 INCHES TOTAL LENGTH

and should be kept in a spacious, mature aquarium with strong filtration, good oxygenation, abundant driftwood, and secure shelters.

This listing is for:

WILD-CAUGHT L137 BLUE EYED RED FIN PLECOS

Current specimens are approximately:

3 INCHES

🔎 Quick Facts – L137 Blue Eyed Red Fin Pleco

📛 Common Name: Blue Eyed Red Fin Pleco
📛 Other Names: Blue-Eyed Redfin Pleco, Rusty Pleco, Violet Pleco, Blue-Eyed Cochliodon Pleco
🔢 L-Number: L137 / L137
🔬 Scientific Name: Hypostomus soniae
🐟 Family: Loricariidae
🧬 Subfamily: Hypostominae
🧬 Species Group: Hypostomus cochliodon Group
🌿 Stock: Wild Caught
📏 Current Size: Approximately 3 inches
🇧🇷 Country: Brazil
🌊 Native Range: Rio Tapajós Basin
📍 State: Pará, Brazil
📍 Type Region: Rio Tapajós between Vila Nova and Uruá
💧 Water Type: Freshwater / Tapajós Clearwater
📏 Scientific Maximum: Approximately 16.37 cm / 6.4 inches standard length
📏 Adult Planning Size: Approximately 7–9 inches total length
🏠 Recommended Aquarium: 75 gallons or larger
👥 Multiple Adults: 90–125+ gallons depending on bottom territory
🌡️ Temperature: Approximately 75–82°F
💧 pH: Approximately 6.0–7.5
💦 Water: Soft to moderately mineralized
💨 Oxygenation: Good to High
🌊 Water Movement: Moderate
🍽️ Diet: Wood-Grazing, Plant-Leaning Omnivore / Detritivore
🪵 Driftwood: Strongly Recommended
🌿 Vegetable Foods: Important
🦐 Animal / Insect Protein: Supplemental
🚫 Algae Cleaner: Should not be purchased solely for algae control
😌 Temperament: Generally peaceful toward other fish
⚠️ Pleco Temperament: Territorial with its own kind and similar plecos
🌙 Activity: Primarily nocturnal / crepuscular, but established fish may be active during daylight
🐠 Swimming Area: Bottom
🥚 Captive Breeding: Not reliably documented in the home aquarium
⭐ Care Level: Intermediate
🌎 IUCN Status: Least Concern

🧬 Correct Scientific Name

The currently accepted scientific name is:

Hypostomus soniae

The species was scientifically described by:

Hollanda Carvalho & Weber

in a paper associated with the 2004 volume of Revue Suisse de Zoologie and formally cataloged as published in:

2005

Modern taxonomic databases continue to recognize:

Hypostomus soniae

as a valid species.

⚠️ Older “Cochliodon” Name

Older aquarium literature may refer to this fish as:

Cochliodon soniae

or simply:

Blue-Eyed Cochliodon

This comes from its relationship to the former genus:

Cochliodon

Species once placed in Cochliodon were later incorporated into:

Hypostomus

and are now commonly discussed as members of the:

Hypostomus cochliodon Group

Therefore, for the current product page use:

**L137 Blue Eyed Red Fin Pleco – (Hypostomus soniae)**

rather than Cochliodon soniae.

🦷 The Hypostomus cochliodon Group

L137 belongs to a particularly interesting lineage within Hypostomus.

Members of this group tend to have:

Higher-backed bodies
Specialized jaws
Relatively few teeth
Broad spoon-shaped or chisel-like teeth
Strong wood-rasping behavior

These teeth differ dramatically from the finer scraping teeth seen in many algae-grazing plecos.

🪵 A True Wood-Grazing Hypostomus

Scientific studies of the Hypostomus cochliodon group have documented digestive tracts containing large quantities of:

WOOD PARTICLES

These fishes occupy a feeding niche remarkably similar to the familiar wood-grazing:

Panaque

plecos.

This makes driftwood especially important in the L137 aquarium.

⚠️ Wood-Eating Does Not Mean “Wood Alone”

The phrase:

Wood-Eating Pleco

can easily be misunderstood.

Wild L137 and related fish do not live on sterile pieces of cellulose.

Natural submerged wood also carries:

Biofilm
Algae
Bacteria
Fungi
Detritus
Microorganisms
Organic material

The fish grazes this entire ecological surface.

Therefore:

WOOD SHOULD NOT BE THE ONLY FOOD PROVIDED

🚫 Do Not Say Wood Is Required “For Digestion”

Many aquarium websites state that wood-eating plecos:

“Need driftwood to digest their food.”

That explanation is too simplistic.

Wood-grazing loricariid research shows these fish consume enormous quantities of wood, but that does not mean they efficiently digest cellulose like a termite or ruminant.

For your website, the more accurate statement is:

DRIFTWOOD IS STRONGLY RECOMMENDED FOR NATURAL GRAZING, BIOFILM, DETRITUS, SHELTER, AND ENRICHMENT.

🔵 The Blue Eyes

The most recognizable feature of L137 is its:

PALE BLUE TO BRILLIANT BLUE EYES

Depending on:

Lighting
Fish condition
Viewing angle
Stress level

the eyes may appear:

Powder blue
Silver-blue
Ice blue
Gray-blue
Almost white with a blue cast

The blue eyes contrast dramatically with the darker body.

🔴 Why “Red Fin”?

The fins may develop warm coloration ranging from:

Rust
Copper
Bronze
Orange-brown
Red-brown
Brick red

The intensity varies considerably between individuals.

The:

Dorsal fin
Caudal fin
Pectoral fins
Pelvic fins

may all display some degree of this warm coloration.

🎨 Body Color

Typical body coloration includes:

Olive-brown
Gray-brown
Rust-brown
Dark gray
Violet-gray
Charcoal

Some individuals develop subtle:

Longitudinal lines
Darker striping
Mottling

rather than obvious spots.

A lack of bold spotting is characteristic of this species.

💜 Why “Violet Pleco”?

Another aquarium name occasionally used for L137 is:

Violet Pleco

This comes from the subtle:

Violet
Purple-gray
Slate
Mauve-brown

tones that can appear through the body under certain lighting.

This coloration can be difficult to appreciate immediately after shipping.

🔄 Color Changes With Stress

Wild-caught L137 may look noticeably dull immediately after transportation.

Shipping stress can cause:

Pale body color
Gray coloration
Reduced red in the fins
Less visible blue in the eyes
Dark stress markings

Once established under good conditions, coloration often becomes much stronger.

⚠️ Color Disclaimer

Exact adult coloration cannot be guaranteed.

Individuals may vary in:

Red-fin intensity
Body darkness
Violet coloration
Eye color intensity
Amount of subtle striping

Appearance is also affected by:

Diet
Lighting
Aquarium background
Water quality
Stress
Acclimation

🌎 Native Distribution

Hypostomus soniae is:

ENDEMIC TO BRAZIL'S RIO TAPAJÓS BASIN

in:

PARÁ, BRAZIL

It should not simply be listed as:

“South America”

when much more precise information is available.

📍 Type Locality

The type material was collected from:

Temporary Pools Along the Rio Tapajós

between:

Vila Nova
Uruá

in:

Pará, Brazil

Additional populations occur through portions of the Tapajós drainage.

🗺️ Restricted Distribution

Recent research has confirmed that Hypostomus soniae has a relatively:

RESTRICTED DISTRIBUTION

within the Tapajós system.

Modern records have been concentrated in portions of:

Pará
Mato Grosso

within the greater Tapajós drainage.

This makes accurate locality information valuable for wild-caught fish.

🌊 Rio Tapajós Habitat

The Tapajós is one of Brazil's major clearwater river systems.

L137 occurs in habitats that can include:

River margins
Rocky substrate
Softer substrate
Temporary riverside pools
Submerged wood
Natural organic material

This is not a fish that requires an artificial extreme-current river tank at all times.

🌊 Water Movement

Provide:

MODERATE WATER MOVEMENT

with good oxygenation.

A suitable aquarium should offer:

🌊 Moving-Water Areas

for:

Oxygenation
Waste removal
Natural behavior

and:

🪵 Protected Areas

around:

Wood
Rocks
Caves

where the fish can rest.

💨 Oxygenation

Good dissolved oxygen is important.

Recommended methods include:

Strong surface agitation
Efficient filter returns
Air stones
Powerheads
Sump filtration
Supplemental circulation

The aquarium should remain:

CLEAN + STABLE + WELL OXYGENATED

🌡️ Temperature

FishBase records an appropriate natural temperature range around:

75–82°F / 24–28°C

This makes a practical aquarium recommendation of:

75–82°F

appropriate.

There is generally no reason to maintain L137 continuously near 87°F simply because some older specialty references list higher temperatures.

💧 Water Parameters

A practical long-term aquarium range is:

🌡️ Temperature: 75–82°F
💧 pH: Approximately 6.0–7.5
💦 Hardness: Soft to moderately mineralized
💨 Oxygenation: Good to High
🌊 Current: Moderate
☠️ Ammonia: 0 ppm
☠️ Nitrite: 0 ppm
🔄 Nitrate: Keep as low as reasonably practical

Stable conditions matter more than constantly attempting to adjust the aquarium to one exact pH.

📏 Adult Size

Current FishBase data document Hypostomus soniae reaching:

16.37 CM / APPROXIMATELY 6.4 INCHES STANDARD LENGTH

Standard length:

DOES NOT INCLUDE THE FULL TAIL FIN

Therefore, for customer planning:

APPROXIMATELY 7–9 INCHES TOTAL LENGTH

is reasonable.

⚠️ Why Some Websites Say 12 Inches

Several older aquarium references give maximum sizes around:

30 CM / 12 INCHES

However, current scientific records are substantially smaller.

Because FishBase provides a documented:

16.37 cm standard length

I would not advertise 12 inches as a normal expected adult size without stronger species-specific evidence.

For Jason's Plecos & Cichlids:

7–9 INCHES ADULT PLANNING SIZE

is the better compromise.

🏠 Aquarium Size

Your older page recommends:

40 Gallons

I would increase permanent adult housing.

For one mature L137:

75 GALLONS OR LARGER

is a better long-term recommendation.

Why?

Because this is a:

High-backed pleco
Heavy grazer
Significant waste producer
Territorial bottom-dweller

that benefits from substantial:

Bottom area
Wood
Shelter
Water volume

👥 Multiple Adults

If keeping:

Multiple L137s
Other Hypostomus
Other substantial plecos

consider:

90–125+ GALLONS

depending on available floor space.

Territory matters as much as total water volume.

📐 Aquarium Footprint Matters

Prioritize:

LENGTH + WIDTH

over excessive aquarium height.

A larger footprint provides room for:

Driftwood
Caves
Feeding areas
Separate territories
Visual barriers

🪵 Aquarium Setup

A good L137 aquarium should contain:

Substantial natural driftwood
Large pieces of wood
Wood cavities
Smooth rocks
Caves
Sand or smooth gravel
Shaded resting areas
Open feeding areas
Strong filtration
Good circulation

Driftwood should be considered:

A MAJOR PART OF THE AQUARIUM ENVIRONMENT

🪵 Recommended Driftwood

Aquarium-safe hardwoods can include:

Malaysian driftwood
Mopani
Bogwood
Manzanita
Other aquarium-safe hardwoods

Provide multiple surfaces the fish can:

Rasp
Rest beneath
Hide around
Establish territory on

🏠 Shelters

L137 should have secure daytime hiding locations.

Suitable options include:

Large driftwood cavities
Ceramic caves
Slate caves
Rock shelters
Wood overhangs

For multiple plecos:

PROVIDE MORE HIDING AREAS THAN FISH

⚠️ Secure the Décor

Adult Hypostomus are powerful fish.

Large specimens can:

Shift lightweight wood
Move stones
Dig under decorations

Make sure all heavy structures are secure.

💩 Significant Waste Production

Wood-grazing plecos can produce:

A LOT OF WASTE

because they constantly process:

Wood particles
Vegetables
Biofilm
Prepared foods
Detritus

Do not assume the fish is “cleaning” the aquarium simply because it eats algae.

💩 Filtration

Strong filtration is important.

Recommended options include:

Large canister filters
Sump filtration
Strong mechanical filtration
High-capacity biological filtration
Supplemental powerheads

Regular partial water changes should be routine.

Maintain:

AMMONIA = 0

NITRITE = 0

and keep nitrate reasonably low.

🍽️ Diet – Wood-Grazing, Plant-Leaning Omnivore

The L137 is best described as a:

WOOD-GRAZING, PLANT-LEANING OMNIVORE / DETRITIVORE

Its diet should contain substantial:

Plant material
Algae-based foods
Detrital foods
Wood-associated biofilm

with:

MODEST SUPPLEMENTAL ANIMAL PROTEIN

🌿 Plant-Based Staple Foods

Suitable staple foods include:

Quality algae wafers
Spirulina wafers
Vegetable-based pleco tablets
Fiber-rich sinking pellets
Quality gel foods

Look for foods containing substantial:

Algae
Plant matter
Vegetable ingredients
Fiber

🥒 Fresh Vegetables

Suitable vegetable foods can include:

Zucchini
Squash
Pumpkin
Sweet potato
Green beans
Kale
Spinach
Appropriate leafy greens

Remove uneaten vegetables before they decay.

🪵 Natural Grazing

A mature aquarium containing:

Driftwood
Natural algae
Biofilm
Organic coatings

provides important supplemental grazing opportunities.

Do not sterilize every surface of the aquarium.

Natural mature surfaces are useful to this species.

🦐 Supplemental Protein

Small amounts of animal food may include:

Bloodworms
Mysis shrimp
Brine shrimp
Insect larvae
Chopped shrimp
Insect-based sinking foods

These should:

SUPPLEMENT THE DIET

rather than dominate it.

🚫 Do Not Feed a Heavy Carnivore Diet

An L137 should not be fed primarily:

Shrimp
Mussel
High-protein carnivore pellets
Large quantities of bloodworms

Its natural trophic adaptations strongly favor:

WOOD-ASSOCIATED AND PLANT-BASED FEEDING

🚫 Not Just an Algae Cleaner

L137 will graze algae.

However:

DO NOT PURCHASE IT SIMPLY TO CLEAN AN AQUARIUM.

A mature L137:

Eats intentionally supplied food
Produces substantial waste
Requires regular maintenance

It is an aquarium animal—not cleaning equipment.

🌿 Plants

Broad-leaved plants may be damaged.

L137 may rasp or consume:

Soft leaves
Dying leaves
Plant surfaces

A delicate planted aquascape may therefore not be the best permanent setup.

Hardier plants may fare better.

🌙 Behavior

L137 is generally:

NOCTURNAL / CREPUSCULAR

but established specimens can become quite active during daylight.

Activity may increase:

At dusk
During feeding
After lights dim

A confident specimen may eventually feed openly while the aquarium lights are on.

🧪 Wild-Caught Acclimation

This listing is for:

WILD-CAUGHT L137 BLUE EYED RED FIN PLECOS

Current specimens are approximately:

3 INCHES

Wild fish deserve careful acclimation.

After arrival:

Provide immediate wood and shelter
Keep lighting subdued
Maintain good oxygenation
Avoid sudden water-chemistry changes
Maintain excellent water quality
Confirm that each fish is eating
Watch body condition carefully

🍽️ Confirm Feeding

A newly imported pleco may hide while faster fish consume its food.

Offer food:

Near the shelter
Beneath driftwood
At dusk
After lights out

Monitor for:

Sunken abdomen
Loss of body mass
Persistent refusal to feed

😌 Temperament

Toward most midwater fish, L137 is generally:

PEACEFUL

It can work well with appropriately selected:

Tetras
Characins
Corydoras-type catfish
Peaceful cichlids
Other community fish

provided aquarium conditions overlap.

⚠️ Territorial With Other Plecos

L137 may be territorial toward:

Other L137s
Other Hypostomus
Similar large plecos

especially around:

Driftwood
Caves
Feeding areas

⚔️ Territorial Behavior

Conflict can include:

Chasing
Pushing
Tail slapping
Blocking shelters

Provide:

Multiple pieces of driftwood
Multiple shelters
Visual barriers
Separate feeding areas

when maintaining more than one substantial pleco.

♂️ Male vs. Female

Reliable external sexing information for Hypostomus soniae is limited.

In related Hypostomus:

Mature Males May Develop

Longer pectoral fins
Thickened first pectoral-fin rays
Stronger odontodes
More territorial behavior

Mature Females May

Become broader through the abdomen
Appear fuller when carrying eggs

However:

DO NOT GUARANTEE SEX FROM THESE FEATURES ALONE

unless the specimen has been confidently identified.

For normal sales:

SELL AS UNSEXED

🧬 Interesting Sex-Chromosome Research

Modern cytogenetic research has made L137 scientifically interesting for another reason.

Researchers studying Hypostomus soniae populations from the Tapajós system have found evidence consistent with a developing:

XX / XY SEX-CHROMOSOME SYSTEM

This research helps scientists better understand how sex chromosomes evolve in South American catfish.

This does not provide an easy visual method for sexing aquarium specimens, but it adds to the scientific significance of the species.

🥚 Breeding

Reliable species-specific captive breeding information for L137 remains:

VERY LIMITED

Current specialist husbandry references continue to report:

NO WELL-DOCUMENTED HOME-AQUARIUM BREEDING METHOD

for Hypostomus soniae.

⚠️ Do Not Automatically Call It a Cave Spawner

Many smaller plecos such as:

Hypancistrus
Peckoltia
Ancistrus

are familiar cave spawners.

That does not mean every Hypostomus species reproduces identically.

Until repeatable breeding observations specifically for L137 are available:

DO NOT INVENT CLUTCH SIZES, CAVE DIMENSIONS, OR INCUBATION TIMES.

🥚 What Can Be Said Safely?

For the product page, the safest wording is:

CAPTIVE BREEDING IS NOT RELIABLY DOCUMENTED

and reproduction should be considered:

AN ADVANCED / EXPERIMENTAL PROJECT

for experienced aquarists.

🔢 L137 & L077

Some older hobby references also associate:

L077

with Hypostomus soniae or closely related Rusty Pleco forms.

However, L-number usage has not always been completely consistent between historical aquarium publications.

For this product:

KEEP THE L137 IDENTIFICATION

unless documented supplier or collection information gives a reason to use another designation.

🆚 L137 & Similar Blue-Eyed Tapajós Plecos

Other blue-eyed Hypostomus-type plecos occur within the broader Tapajós drainage.

L137 should therefore not be identified by:

BLUE EYES ALONE

when locality or supplier identification is uncertain.

Preserve:

L-number
Collection locality
Supplier identification

whenever possible.

🌎 Conservation Status

Hypostomus soniae is currently classified as:

LEAST CONCERN

However, this deserves context.

The species is:

ENDEMIC TO THE TAPAJÓS BASIN

and has a relatively restricted natural distribution.

⚠️ Habitat Pressures

Recent scientific research notes environmental pressures within the region including:

Infrastructure development
Artisanal gold mining
Agricultural expansion
Aquatic pollution
Habitat alteration

The species is also commercially harvested for the ornamental-fish trade.

🎣 Ornamental Fish Trade

L137 is an established Brazilian ornamental species.

Recent research examined its fishery and trade through:

Pimental
Itaituba
Santarém

Thousands of H. soniae have historically entered the ornamental trade.

Brazil regulates the legal capture and sale of native ornamental species.

Responsible sourcing and proper permanent aquarium care remain important.

⭐ Why Keep an L137 Blue Eyed Red Fin Pleco?

The L137 offers an unusual combination of:

🔵 Brilliant blue eyes
🔴 Rust-red to orange fins
💜 Violet-gray body tones
🪵 Fascinating wood-grazing behavior
🦷 Specialized spoon-shaped teeth
🌊 Rio Tapajós origin
🌙 Nocturnal personality
📏 Manageable 7–9 inch adult planning size
🧬 Interesting Hypostomus cochliodon group biology
🔬 Modern genetic and conservation research

that makes it very different from the typical large Common Pleco.

A mature L137 displaying bright blue eyes and warm rust-colored fins can become an impressive centerpiece bottom-dweller.

⚠️ Important Considerations

Before purchasing an L137 Blue Eyed Red Fin Pleco:

The correct scientific name is Hypostomus soniae.
Older literature may use Cochliodon soniae.
The species belongs to the Hypostomus cochliodon group.
This listing is for wild-caught fish.
Current specimens are approximately 3 inches.
L137 is endemic to Brazil's Rio Tapajós Basin.
Use Rio Tapajós, Pará, Brazil rather than simply “South America.”
FishBase documents approximately 6.4 inches standard length.
Standard length excludes the full tail.
Plan for approximately 7–9 inches total adult length.
Provide approximately 75 gallons or larger.
Use larger aquariums for multiple substantial plecos.
Provide significant natural driftwood.
Wood-grazing is an important natural behavior.
Do not claim wood must be digested for proper digestion.
Wood alone is not a complete diet.
Feed plant-based foods, vegetables, algae-based foods, and biofilm-oriented foods.
Provide modest supplemental animal and insect protein.
Do not maintain L137 on a meat-heavy diet.
Do not purchase it simply as an algae cleaner.
Maintain approximately 75–82°F.
Maintain good to high oxygenation.
Provide moderate current.
Keep ammonia and nitrite at zero.
Expect substantial waste production.
Use strong filtration.
Expect territorial behavior toward similar plecos.
Captive breeding is not reliably documented.
Do not invent cave-spawning details for this species.
Preserve L-number and locality information.
Never release aquarium fish into natural waterways.

🧬 Taxonomy

The currently accepted scientific name is:

Hypostomus soniae Hollanda Carvalho & Weber, 2005

Classification:

Order: Siluriformes
Family: Loricariidae
Subfamily: Hypostominae
Genus: Hypostomus
Species: soniae
Species Group: Hypostomus cochliodon Group
L-Number: L137

Older aquarium terminology may include:

Cochliodon soniae
Blue-Eyed Cochliodon
Rusty Pleco
Violet Pleco

For this product, use:

**L137 Blue Eyed Red Fin Pleco – (Hypostomus soniae)**

🪵 Wood-Grazing Disclaimer

L137 belongs to a specialized wood-grazing lineage of Hypostomus.

Natural aquarium-safe driftwood is strongly recommended.

Wood provides:

Natural grazing surfaces
Biofilm
Detritus
Organic material
Shelter
Territory
Environmental enrichment

However:

DO NOT RELY ON DRIFTWOOD AS THE FISH'S ONLY FOOD

and do not claim that wood is required specifically because the fish must digest cellulose.

Provide a varied diet with substantial plant-based nutrition.

🚚 Live Fish Shipping

Live fish are professionally packed for safe transport.

Shipping availability depends on:

Fish size
Destination
Weather conditions
Carrier availability
Applicable state and local regulations

Larger adults may require:

Larger insulated shipping boxes
Additional water
Heavy-duty shipping bags
Specialized packing

Please review our Shipping & Payment Information and Live Arrival Guarantee / DOA Policy before ordering.

⚠️ Buyer Responsibility

Customers are responsible for confirming that Hypostomus soniae may legally be purchased, possessed, transported, and received in their state or local jurisdiction before ordering.

Never release aquarium fish into natural waterways.